Downsampling source space to AAL atlas

Hi Brainstorm engineers,

I'm trying to downsample source space data to AAL atlas space so to reduce PLS workload. My problem is I cannot find the AAL atlas from the 'downsample to atlas -> select atlas' tab.
Now I have added AAL3 in MNI Parcellation and created surfaces from the atlas.
My question is what else is needed to add the atlas to my source space? Thank you so much!

Best,
Victoria

Hi @VICTORIALIU,

The AAL atlas is a volume atlas, not a surface atlas.
Check this post:

It is possible to import the AAL atlas, but for sources resulting from volume source estimation:
https://neuroimage.usc.edu/brainstorm/Tutorials/TutVolSource#Volume_atlases

However the process Sources > Downsample to atlas is not supported for volume grids.

In addition, this process is not recommended.
To obtain one time series per scout use the process Extract > Scouts time series

Best,
Raymundo

Hi Raymond,
Thank you so much for your prompt reply! It is most helpful! I just have one question for clarification, so the AAL atlases, no matter the version, are not for cortical source estimation? Only for volume? Or is that just the AAL3 cortical atlas has not been developed yet, and I can use previous versions. Thank you so much! I'm trying to find the atlas that best captures the ROIs I'm interested in, but the warping process is such a pain.

Best,
Victoria

The AAL atlas has been developed as a volume parcellation in MNI space, there is no cortical version of it.